Strong authentication is the most effective measure against external threats to an organization’s confidential information. Confidential information is any data or information that is sensitive, proprietary, or valuable to the organization, and that should not be disclosed to unauthorized parties1. External threats are malicious actors outside the organization who attempt to gain unauthorized access to the organization’s networks, systems, and data, using various methods such as malware, hacking, or social engineering2. Strong authentication is a method of verifying the identity and legitimacy of a user or device before granting access to the organization’s resources or data3. Strong authentication typically involves the use of multiple factors or methods of authentication, such as passwords, tokens, biometrics, orcertificates4. Strong authentication can prevent or reduce the risk of external threats to the organization’s confidential information, by making it more difficult and costly for the attackers to compromise the credentials or devices of the authorized users, and by limiting the access to the data or resourcesthat are relevant and necessary for the users’ roles and responsibilities5. The other options are not the most effective measures against external threats to the organization’s confidential information, as they are either less secure or less relevant than strong authentication. Single sign-on is a method of allowing a user to access multiple systems or applications with a single set of credentials, without having to log in separately for each system or application6. Single sign-on can improve the user experience and convenience, as well as reduce the administrative burden and cost of managing multiple accounts and passwords. However, single sign-on is not the most effective measure against external threats to the organization’s confidential information, as it can also increase the risk of credential compromise or misuse, and create a single point of failure or attack for the attackers to access multiple systems or data. Data integrity checking is a method of ensuring that the data or information is accurate, complete, and consistent, and that it has not been altered or corrupted by unauthorized parties or processes. Data integrity checking can involve the use of techniques such as checksums, hashes, digital signatures, or encryption. Data integrity checking can enhance the quality and reliability of the data or information, as well as detect and prevent any unauthorized or malicious changes or tampering. However, data integrity checking is not the most effective measure against external threats to the organization’s confidential information, as it does not prevent or reduce the risk of data theft or leakage, and it does not verify the identity or legitimacy of the users or devices accessing the data. Intrusion detection system is a system that monitors the network or system activities and events, and detects and alerts any suspicious ormalicious behaviors or anomalies that may indicate an attempted or successful breach or attack. Intrusion detection system can help to identify and respond to external threats to the organization’s networks, systems, and data, by providing visibility and awareness of the network or system status and activities, and by enabling timely and appropriate actions or countermeasures. However, intrusion detection system is not the most effective measure againstexternal threats to the organization’s confidential information, as it is a reactive or passive system that does not prevent or block the attacks, and it may generate false positives or negatives that can affect its accuracy and efficiency. References = Risk and Information Systems Control Study Manual, 7th Edition, Chapter 4, Section 4.2.1, Page 189.
